Research On Well Log Evaluation Of Ma5 Carbonate Reservoirs In West Of Jing Bian Gasfield

In the world, there are many large, high-yield oil and gas carbonate reservoir, its reserves accounted for about 50% of the world’s oil and gas reserves. The heterogeneity, complex rock composition and characteristics of low porosity, permeability of fractured carbonate reservoir makes the research of lithology, physical property, gas-bearing, reservoir recognition and classification more difficult. Reasonable and effective logging evaluation is of great significance for the guidance of carbonate reservoir exploration and development.Based on the Ma5 carbonate reservoir in west of JingBian gasfield, the paper analyses the geological situation and the characteristics of reservoir lithology and physical properties. According to the lithology characteristics of carbonate reservoir in the study area, the neutron-density is used to identify the lithology. Considering the factors such as hole enlargement have great effect on the quality of the logging curve, which makes more error in the lithology identification. We calculate mineral contents by using photoelectric absorption cross section index in hole enlargement section, which make up the shortcomings and deficiencies of cross-plot method and have a good application effect in west of JingBian gasfield. According to the characteristics of the fractured carbonate reservoir, the research of reservoir matrix porosity, fracture permeability, fracture porosity, matrix permeability model and FMI porosity spectrum have been conducted, a new permeability model based on porosity spectrum was proposed for the first time. Analyzed and summarized the main method of carbonate reservoir water saturation in this paper, the model based on pore types and the archie saturation model, based of variable m value was used in the paper. The fluid movement index, based on array acoustic logging, have achieved good effect in carbonate reservoir recognition, which makes up for the leakage of conventional logging in identifying permeable formation. Reservoir classification based on pore structure and production was carried on after the above research. Considering the difficulty of fluid identification in carbonate reservoir, the imaging logging data was used in this paper, the Induction logging-lateral logging crossplot method, the rock elastic mechanics parameter method, the electric imaging apparent formation water resistivity spectrum of three kinds of fluid identification method was used and the good results have been achieved in fluid identification in the study area.